How to start developing VoIP applications via Asterisk PBX?

:smiley: Thanks Rusty for your reference url. I’ve been to this url before. My problem is that I dont know how to start to modify the Asterisk source codes and build it again.

My project will be developing a VoIP applications featuring Asterisk PBX that can be used in the office. Any idea how to start?

Does VoIP applications equals to softphones ?